Browse the evidence

BMI is an inadequate measure of obesity because it does not distinguish between lean muscle mass and adipose tissue, leading to misclassification of metabolic health.

Don't rely on BMI alone. If you have a normal BMI but feel unwell, ask about waist circumference and metabolic health. If you have a high BMI but are muscular, focus on metabolic markers rather than just weight.

When subcutaneous white adipose tissue (scWAT) reaches its maximal storage capacity, it becomes dysfunctional and fails to store lipids appropriately, leading to ectopic fat accumulation in the liver and visceral depots, thereby causing non-alcoholic fatty liver disease (NAFLD).

If you are obese, your body's ability to store fat safely in your subcutaneous areas (like thighs and arms) may be maxed out. Once this 'buffer' is full, excess fat spills over into your liver and visceral organs, causing disease. Strategies to improve metabolic health should focus on preventing this overflow, potentially through interventions that support adipose tissue health or reduce caloric intake to match storage capacity.

Reduction of adipocyte-derived SPARC protects against high-fat diet-induced obesity and metabolic dysfunction in female mice by enhancing energy expenditure and lipolysis.

This research identifies SPARC, a protein elevated in obesity, as a key regulator of fat storage. Reducing SPARC (naturally via caloric restriction or potentially via future therapies) may help manage weight by increasing energy expenditure and breaking down fat, particularly in women. While not a direct diet advice, it highlights that lowering this specific protein is linked to improved metabolic health.

Pharmacological activation of brown and beige adipose tissue thermogenesis via beta-3 adrenergic signaling or UCP1-independent futile cycles increases energy expenditure and improves systemic metabolic health.

Your fat tissue is not just storage; it actively regulates your metabolism. While cold exposure can activate brown fat, current medical strategies focus on pharmacological agents (like GLP-1 agonists) that may indirectly support metabolic health. Understanding that visceral fat is metabolically harmful while subcutaneous fat is more neutral can guide lifestyle choices, but surgical removal of fat is not a cure for metabolic disease.

Global Positioning Systems (GPS) and metabolic power calculations tend to underestimate energy expenditure during soccer match-play compared to indirect calorimetry, particularly during recovery phases.

Be cautious when using GPS devices to estimate calorie burn. They often underestimate energy expenditure, especially during rest periods in soccer. Use this data as a rough guide rather than an exact number when planning nutrition.

In strength-trained individuals, acute carbohydrate intake does not improve resistance training performance (repetitions to failure or total volume) when compared to a fed state with a 2-5 hour post-prandial window, provided the workout volume is moderate (≤10 sets per muscle group).

If you eat a normal meal 2-5 hours before lifting, you do not need to force-feed yourself carbohydrates right before training to get better reps or strength. Your muscles have enough glycogen. Save the carbs for post-workout or general daily intake. If you train fasted or do extremely high volume (>10 sets/muscle), then carbs may help, but for standard sessions, don't stress about pre-workout carbs.

Bariatric surgery reduces all-cause and cardiovascular mortality and heart failure incidence, but its effect on reducing *incident* atrial fibrillation is not statistically significant.

Bariatric surgery significantly reduces death and heart failure in obese patients, but it does not significantly reduce the risk of *developing* new atrial fibrillation. It is still beneficial for overall heart health.

Ketogenic diets (KD) do not independently reduce energy intake or increase energy expenditure compared to non-ketogenic diets when energy density and behavioral factors are controlled; any observed weight loss is attributable to caloric deficit rather than ketosis itself.

If you are choosing a diet for weight loss, know that a ketogenic diet is not metabolically superior to a high-carbohydrate diet in terms of appetite control or energy expenditure. You will lose weight on either diet if you maintain a caloric deficit. Do not expect ketones to magically suppress your hunger or boost your metabolism beyond what is achieved by simply eating fewer calories.

Rapid and substantial weight reduction, such as that achieved by bariatric surgery or certain medications, may result in greater reductions in lean muscle mass compared to gradual weight reduction.

If you are undergoing rapid weight loss (e.g., surgery or strong medications), prioritize resistance training and adequate protein intake to protect your muscle mass. Monitor your body composition, not just scale weight, to ensure you are losing fat, not muscle.

Hepatic protein kinase Cbeta (PKCβ) deficiency mitigates late-onset obesity in mice by increasing energy expenditure through β3-adrenergic receptor signaling, independent of FGF21.

This research suggests that as we age, our liver may produce more PKCβ, which can suppress our body's ability to burn fat and heat (thermogenesis). While you cannot change your genetics, maintaining liver health through regular physical activity—which is shown to repress PKCβ expression—may help preserve your metabolic rate and resistance to age-related weight gain.

Increasing resistance training volume from moderate (3 sets/exercise) to high (5 sets/exercise) does not improve lean mass or muscle thickness preservation during a moderate caloric deficit in trained males.

If you are dieting to lose fat but want to keep your muscle, you do not need to drastically increase your training volume. A moderate volume (e.g., 3 sets per exercise) is just as effective as high volume (5 sets) for preserving muscle mass, provided you are eating enough protein (approx. 2.8g/kg FFM) and maintaining a moderate caloric deficit. Focus on keeping weights heavy (close to failure) rather than adding extra sets.

Energy-restricted diets have limited efficacy in reducing body fat and preventing cardiovascular events in T2DM compared to metabolic surgery or newer pharmacological interventions.

While healthy eating is crucial for T2DM, energy-restricted diets alone may not significantly reduce body fat or prevent heart problems in the long term. Combining diet with newer medications that target fat loss may be more effective.

Obesity severity (Class I, II, III) is directly correlated with increased direct medical costs, with Class III obesity costing up to 3.3 times more than normal weight individuals.

Higher obesity classes (II and III) are associated with significantly higher medical costs (up to 3.3x normal weight). This highlights the economic urgency of addressing obesity, especially in higher severity classes, through early intervention.

High host-driven digestibility (HDD) diets, such as ultra-processed foods, decouple host and microbial nutrient status by maximizing small intestinal absorption, which leads to host energy surplus and gut microbial nutrient limitation.

To optimize gut health and metabolic balance, prioritize foods with low host-driven digestibility (high fiber, resistant starch, whole foods). These foods escape small intestinal absorption, reaching the colon to feed beneficial microbes, which in turn produce short-chain fatty acids that support host health. Ultra-processed, high-digestibility foods absorb quickly, leading to host energy surplus and starving the gut microbiome.

Bariatric surgery significantly reduces the incidence of obesity-associated cancers and cancer-specific mortality compared to non-surgical controls.

For individuals with morbid obesity, bariatric surgery is a highly effective intervention for reducing cancer risk. Discuss surgical options with a specialist if lifestyle changes are insufficient.

High cardiorespiratory fitness (CRF) mitigates or eliminates the 'obesity paradox' in heart failure, meaning overweight patients with high CRF do not have better survival than normal-weight patients with low CRF.

For heart failure patients, being overweight is not inherently protective if you are unfit. High cardiorespiratory fitness (CRF) is the key determinant of survival. Focus on improving your fitness through exercise (like the 6-minute walk test or CPX) rather than just focusing on BMI, as high fitness eliminates the 'obesity paradox' survival advantage.

High intake of dietary fructose (common in Western diets) metabolically rewires innate immunity by increasing mTORC1 activity and IL1B expression in monocytes/macrophages, thereby promoting a pro-inflammatory state and reducing metabolic flexibility.

If you consume a diet high in processed foods containing corn syrup or high-fructose ingredients, you may be inadvertently keeping your immune system in a state of low-grade alert. This happens because fructose pushes immune cells to prioritize inflammatory signaling over metabolic flexibility. Reducing processed fructose intake can help restore normal immune metabolic function.

Obesity and the associated accumulation of bone marrow adipocytes disrupt normal hematopoiesis and immune function by creating a pro-inflammatory environment mediated by TLR4 activation, leading to impaired immune responses and increased morbidity/mortality during infections.

Obesity is not just a metabolic issue; it biologically alters your bone marrow environment. Excess fat in the marrow drives chronic inflammation and impairs the production and function of immune cells, making infections more dangerous. Managing weight can help restore normal immune niche function.

GLP-1 receptor agonist therapy induces predictable reductions in fat-free mass (approximately 30-40% of total weight loss) due to sustained negative energy balance, not direct catabolic effects.

Expect that about a third of your weight loss on GLP-1s will be muscle/fluid, not just fat. This is normal physiology, not a side effect. To mitigate this, prioritize protein intake and resistance training, especially if you have low testosterone.

Higher body mass index (BMI) causes structural remodeling of the right ventricle, specifically increasing end-diastolic and end-systolic volumes, independent of left ventricular measures.

Maintaining a healthy BMI is crucial for protecting the structure of your right ventricle. This study shows that higher body weight is causally linked to larger heart volumes, which can lead to dysfunction over time. Weight management strategies, including diet and exercise, can help prevent this structural remodeling.

Tirzepatide improves metabolic and inflammatory markers in alcohol-consuming rodents, including reducing body weight, white adipose tissue, hepatic triglycerides, and pro-inflammatory cytokines.

Tirzepatide improves metabolic health and reduces inflammation in alcohol-consuming rodents, potentially addressing comorbidities of AUD.

Higher BMI (Class 2+ obesity, ≥35 kg/m2) is consistently associated with increased odds of mobility, severe mobility, and IADL disability in older adults with type 2 diabetes, regardless of intervention group.

Maintaining a BMI below 35 kg/m2 is crucial for preserving mobility and independence in older adults with type 2 diabetes. While moderate weight loss might not be the primary goal for everyone, avoiding Class 2+ obesity (BMI ≥35) is strongly associated with lower risks of severe mobility and instrumental activities of daily living (IADL) disability.

Bariatric surgery (RYGB, Sleeve Gastrectomy) significantly reduces long-term cardiovascular mortality and incidence of coronary heart disease, stroke, and myocardial infarction compared to non-surgical management.

For severe obesity, bariatric surgery is the most effective long-term treatment for preventing heart attacks, strokes, and death. It works by creating lasting metabolic changes and weight loss.

The rates of CVD and death are higher in men compared to women and in rural compared to urban areas.

Public health interventions should target men and rural populations to reduce CVD incidence.